The invention generally relates to laminating magnetic materials in a semiconductor device.
A semiconductor package (or chip) may include a voltage regulator that is fabricated in a die of the package. The voltage regulator typically includes an inductive component, such as an inductor or transformer, which the regulator energizes and de-energizes for purposes of regulating an output voltage of the regulator.
Conventionally, an integrated inductive component of the voltage regulator may be formed by depositing a magnetic metal layer on the die, which forms a magnetic core for the inductive component. Due to the nature of magnetic materials, during operation, the magnetic metal layer may give rise to significant eddy currents, which result in power losses. As a more specific example, conventional magnetic metal materials, such as phase vapor deposited CoZrTa and electroplated NiFe, have resistivities of 100 μΩ·cm or lower. The resulting power loss from eddy currents in the magnetic metal layer may contribute significantly to the overall power loss for the voltage regulator.
Thus, there is a continuing need for better ways to fabricate a magnetic core in a semiconductor device.